JP2007285575A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger capable of keeping a surface temperature of a heat exchange container in a maximum temperature state. <P>SOLUTION: The plurality of heat exchange containers 1 are connected to a steam supply pipe 2 through a steam ejector 5. A steam trap 4 is mounted at a downstream side of the heat exchange container 1 through a condensate discharge pipe 3 and a gas-liquid separation tank 10. A lower end portion of a branch pipe 7 is connected to an upper portion of the gas-liquid separation tank 10, and an upper end portion of the branch pipe 7 is connected to a suction chamber 6 of the steam ejector 5. A liquid pressure-feeding member 14 is connected to an outlet side of the steam trap 4. The steam and the condensate in the heat exchange container 1 flow down to the gas-liquid separation tank 10 from condensate discharge pipe 3, and the steam is sucked to the steam ejector 5, thus the steam in the heat exchange container 1 is forcibly convected/circulated, and the surface temperature of the heat exchange container 1 can be kept in the maximum temperature state. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat exchanger that heats an object to be heated using steam as a heat source.

Conventional heat exchangers connect a steam supply pipe that supplies steam to a number of cylinders and dryers and a discharge pipe that discharges condensate with condensed steam, and separates the steam into this steam supply pipe and condensate discharge pipe. The steam separators are connected to each steam separator, and a steam trap is attached to each steam separator, so that condensate can be eliminated from a large number of cylinder dryers. Here, a steam trap (also called a steam trap) is an automatic valve that automatically discharges only condensate from the gas-liquid two-phase fluid of steam and condensate, and does not discharge steam to the outside. It is a kind of.

The conventional heat exchanger has a problem that the surface temperature of many cylinders and dryers cannot be maintained at the maximum temperature in the apparatus. This is probably because the steam for heating inside the cylinder dryer is not sufficiently convected.
Japanese Utility Model Publication No. 60-40499

  The problem to be solved is to obtain a heat exchanger capable of maintaining the surface temperature of a heat exchange vessel such as a cylinder / dryer at the maximum temperature by promoting convection of steam for heating inside the cylinder / dryer. That is.

  In the present invention, a steam supply pipe and a condensate discharge pipe are connected to a plurality of heat exchange containers to heat an object to be heated with the steam supplied from the steam supply pipe, and the steam is deprived of heat from the condensate discharge pipe. The condensate condensed and discharged is discharged from the system by interposing a steam ejector in the steam supply pipe, attaching a steam trap to multiple condensate discharge pipes, and connecting a branch pipe from the inlet side of the steam trap. The ends of the plurality of branch pipes are connected to the suction chamber of the steam ejector, and the outlet side of the steam trap is connected to the liquid pumping member.

  The present invention provides a suction chamber of a steam ejector by connecting a steam trap inlet attached to a condensate discharge pipe and a suction chamber of the steam ejector by a branch pipe with a steam ejector interposed in the steam supply pipe. The steam in the heat exchange vessel can be forcibly convected through the branch pipe with the suction force generated in step 1, and the surface temperature of the heat exchange vessel can be maintained at the maximum temperature state.

  In the present invention, the suction chamber of the steam ejector and the inlet side of the steam trap are connected by a plurality of branch pipes. The branch pipes on the suction chamber side of the steam ejector are individually connected to the plurality of branch pipes. Alternatively, a plurality of branch pipes can be combined into one and connected to the suction chamber.

  In FIG. 1, a plurality of heat exchange containers 1 that exchange heat with an object to be heated, a steam supply pipe 2 that supplies steam to the heat exchange container 1, and a condensate discharge pipe 3 that discharges condensate in the heat exchange container 1. A steam trap 4 attached to each condensate discharge pipe 3, a steam ejector 5 interposed in the steam supply pipe 2, and a branch pipe connecting the suction chamber 6 of the steam ejector 5 and the inlet side of the steam trap 4. 7 and the liquid pumping member 14 disposed on the outlet side of the vapor trap 4 constitute a heat exchanger.

A control valve 8 and a steam ejector 5 are attached to the steam supply pipe 2 for controlling the steam pressure supplied to the plurality of heat exchange containers 1 to a predetermined value. The steam ejector 5 is composed of a suction chamber 6 having a nozzle and a diffuser 9, and generates a predetermined suction force in the suction chamber 6 when the steam flows down at a high speed.

The heat exchange container 1 is a cylindrical roll in the present embodiment, and is heated by steam inside the roll 1 while an object to be heated such as long paper (not shown) or fiber passes through the outer surface of the roll 1. The condensate that is heated to a predetermined temperature and deprived of heat inside the roll 1 is discharged from the condensate discharge pipe 3 and the steam trap 4 to the downstream side.

  A gas-liquid separation tank 10 is attached to the steam trap 4 inlet side of the condensate discharge pipe 3, a lower end portion of the branch pipe 7 is connected to an upper portion of the gas-liquid separation tank 10, and an upper end portion of the branch pipe 7 is connected to the steam ejector 5. The suction chamber 6 is connected. Valves 11 and 12 are attached to the branch pipe 7 respectively.

  In the gas-liquid separation tank 10, the mixed fluid of steam and condensate flowing down from the heat exchange container 1 is temporarily accumulated, the condensate is located in the lower part thereof, and the steam is located in the upper part thereof. Condensate in the gas-liquid separation tank 10 flows down from the steam trap 4 on the downstream side to the liquid pumping member 14 below.

  The steam in the gas-liquid separation tank 10 is sucked into the steam ejector 5 by the suction force generated in the suction chamber 6 of the steam ejector 5, mixed with the steam supplied from the steam supply pipe 2, passes through the diffuser 9, and the heat exchange container 1. Supplied to. As described above, the steam in the heat exchange container 1 is forcibly convected and circulated by the suction force of the steam ejector 5, thereby improving the heating efficiency in the heat exchange container 1. The surface temperature can be maintained at the maximum temperature state.

The liquid pumping member 14 has a liquid inlet 15, a liquid outlet 16, a high-pressure operating fluid inlet 17 and a high-pressure operating fluid outlet 18, and supplies condensed water to the liquid inlet 15 via a check valve 19. Connect the tube 20. The upper part of the condensate supply pipe 20 is connected to a condensate header tank 21. The upper part of the condensate header tank 21 is connected to the outlet side of the steam trap 4.

The check valve 19 attached to the condensate supply pipe 20 allows the liquid to flow from the condensate supply pipe 20 into the liquid pumping member 14 and prevents the opposite liquid flow. Similarly, a condensate pressure feeding pipe 23 is connected to the liquid outlet 16 via a check valve 22. The check valve 22 has a function of allowing the liquid to flow from the liquid pumping member 14 to the condensate pumping pipe 23 and blocking the opposite flow.

A high-pressure steam pipe 24 branched from the steam supply pipe 2 is connected to the high-pressure operating fluid introduction port 17. On the other hand, the high-pressure operating fluid discharge port 18 is connected to the branch pipe 7 through a communication pipe 25 with a valve 13 interposed therebetween, and communicates with the suction chamber 6 of the steam ejector 5.

The liquid pumping member 14 closes the high-pressure operating fluid introduction port 17 and opens the high-pressure operating fluid discharge port 18 when a float (not shown) disposed therein is located in the lower part, and opens the condensate supply pipe 20. Then, the condensate flows down into the liquid pumping member 14 through the check valve 19 and the liquid inflow port 15, and the vapor in which the condensate re-evaporates inside the liquid pumping member 14 is sucked into the suction chamber 6 of the steam ejector 5.

When condensate accumulates in the liquid pumping member 14 and a float (not shown) is positioned at a predetermined upper portion, the high-pressure operation fluid discharge port 18 is closed to stop the re-evaporated vapor suction, while the high-pressure operation fluid introduction port 17 is Opening and allowing high-pressure pressure-feeding steam to flow into the inside from the high-pressure steam pipe 24, the condensate accumulated inside is pumped to a predetermined location through the liquid outlet 16, the check valve 22 and the condensate pressure-feed pipe 23.

  When the condensate is pumped and the liquid level in the liquid pumping member 14 is lowered, the high-pressure operating fluid inlet 17 is closed again, and the high-pressure operating fluid outlet 18 is opened again. While being caused to flow down, the re-evaporated steam of the condensate is sucked into the steam ejector 5. By repeating such an operation cycle, the liquid pumping member 14 pumps the condensate discharged from the steam trap 4 to a predetermined location.

The block diagram which shows the Example of the heat exchanger of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat exchange container 2 Steam supply pipe 3 Condensate discharge pipe 4 Steam trap 5 Steam ejector 6 Suction chamber 7 Branch pipe 9 Diffuser 10 Gas-liquid separation tank 14 Liquid pumping member 15 Liquid inlet 16 Liquid outlet 17 High pressure operation fluid Inlet 18 High pressure operation fluid inlet 20 Condensate supply pipe 21 Condensate header tank 23 Condensate pressure feed pipe

Claims (1)

A steam supply pipe and a condensate discharge pipe are connected to a plurality of heat exchange containers to heat the object to be heated with the steam supplied from the steam supply pipe, and at the same time, the steam is decondensed due to heat being removed from the condensate discharge pipe. In the case of discharging water out of the system, a steam ejector is interposed in the steam supply pipe, a steam trap is attached to a plurality of condensate discharge pipes, a branch pipe is connected from the inlet side of the steam trap, and the plurality of A heat exchanger characterized in that an end of a branch pipe is connected to a suction chamber of a steam ejector, and an outlet side of the steam trap is connected to a liquid pumping member.

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